1. Field of the Invention
This invention relates broadly to releasable tow hooks. More particularly, it concerns hook devices with which a tow line may be attached to a towed object, e.g., a a manned submersible, and then detached remotely.
2. Description of the Prior Art
There is a need in many different type operations for hook devices by which a line may be temporarily connected to the hook device and later released from a location remote from the hook device. The need for the remote releasing may be (a) to protect the person making the release from injury, (b) because the hook device at the time of required release is inaccessible to the operator, etc.
In simpler types of remote release hook devices, the release is performed by a lanyard or like line. Such units have been designed for helicopter cargo loading hooks (U.S. Pat. No. 3,068,034), mooring bouys (U.S. Pat. No. 3,193,318), load lifting hooks (U.S. Pat. No. 3,918,758) and raft & boat davits (U.S. Pat. No. 4,379,579).
In more complicated types of remote release hook devices, the release is performed by radio control, hydraulic lines, or other means more complex than a lanyard. For example, such units have been used for safety purposes in the mooring of ships and boats to a dock, e.g., see U.S. Pat. Nos. 3,811,720; 4,034,992 and 4,389,907.
The present invention relates to remote release hook devices of the latter type particularly designed for use in the towing of submersible vessels.
In the launching and recovery of a manned submersible, a tow line is attached thereto by which it may be towed to a desired location and then released. In order to effect such release without use of a diver to accomplish it, some form of hook device is needed to permit a person in the submersible or at some other remote location to release the tow line to enable the submersible to then proceed under its own power to perform whatever task has been assigned to it.
The present invention provides improved remote control release hook devices that are particularly useful in the towing of submersible vessels, but which may also be adapted for use in a variety of other applications.